Chimney Flue Hole

We are preparing to put a Class A Chimney Flue through our metal roof (4/12 pitch) which also has OSB sheathing on 16 inch center scissor trusses. We are considering triple wall which we understand can be installed 2 inches from combustibles. We'll need to put the pipe through the small attic area (24 inches high). Has anyone lined that flue space with Durock? Or how have you addressed the issue?

Any suggestions on cutting the hole in the roof? Round? Square? What tool?

And what is the best high temperature flashing to use?

Thanks!
Liz

Advertisement

Chimney Flue Hole

We are preparing to put a Class A Chimney Flue through our metal roof (4/12 pitch) which also has OSB sheathing on 16 inch center scissor trusses. We are considering triple wall which we understand can be installed 2 inches from combustibles.
That's fine.

Has anyone lined that flue space with Durock? Or how have you addressed the issue?

No need to worry about that space.

Any suggestions on cutting the hole in the roof? Round? Square? What tool?

Round, about 2" larger than the pipe.

And what is the best high temperature flashing to use?
The metal collar is fire-proof.

Chimney Flue Hole

Chimney Flue Hole

So I called a place that sells chimney pipe and he says double wall pipe is a better product than triple wall because it has insulation in it. And 2 inches of clearance to combustibles is what is needed. He also says they have boxes that go around the pipe through the attic... anybody have experience with this?